What describes the role of the rotor in an induction motor?

• A. It provides electrical resistance
• B. It is a passive element that rotates due to the stator's magnetic field
• C. It generates its own magnetic field
• D. It alters the frequency of the output

Answer: (B)

The rotor in an induction motor plays a crucial role as a passive element that rotates in response to the magnetic field produced by the stator. When alternating current flows through the stator windings, it generates a rotating magnetic field. This magnetic field induces current in the rotor conductors through electromagnetic induction. As a result, the rotor experiences a force due to the interaction between its induced magnetic field and the stator's rotating magnetic field, causing it to rotate.

This passive behavior is fundamental to the operation of induction motors, as the rotor does not require an external power source to generate its magnetic field, which differentiates it from motors that rely on additional excitation. Therefore, the description that the rotor "is a passive element that rotates due to the stator's magnetic field" accurately captures its function in an induction motor.